NaRbO
Cast Iron
- Joined
- Nov 22, 2006
- Location
- Windsor ON
I've been having some issues with longer reach carbide endmills in hardened h13 tool steel, about 45-48Rc.
The endmills i'm using are mostly OSG and also some Hitachi. We just ran two 3mm OSG WXL ball nose cutters. One had a 12mm reach and the other a 20mm reach. Machine has a max of 15000 rpm. Both cutters were ran at 15000rpm and 51ipm. the 12mm reach ran fine but the 20mm reach tool chipped and left material where it needed to blend. I re ran that tool at 42ipm with a new endmill and it cleaned up but still left a little step and there was a partial chip in one of the flutes after it finished. this is a finishing pass with .003" stock on the mold and a .004" stepdown.
Basically what I do is alter rpm and chipload by a certain percent based on the length to diameter ratio. But i can't seem to find any kind of consistancy with the longer tools. I'm using shrink fit and precision collet holders.
Does anyone have any tips or formulas for these type of situations?
Thanks
The endmills i'm using are mostly OSG and also some Hitachi. We just ran two 3mm OSG WXL ball nose cutters. One had a 12mm reach and the other a 20mm reach. Machine has a max of 15000 rpm. Both cutters were ran at 15000rpm and 51ipm. the 12mm reach ran fine but the 20mm reach tool chipped and left material where it needed to blend. I re ran that tool at 42ipm with a new endmill and it cleaned up but still left a little step and there was a partial chip in one of the flutes after it finished. this is a finishing pass with .003" stock on the mold and a .004" stepdown.
Basically what I do is alter rpm and chipload by a certain percent based on the length to diameter ratio. But i can't seem to find any kind of consistancy with the longer tools. I'm using shrink fit and precision collet holders.
Does anyone have any tips or formulas for these type of situations?
Thanks